Steering-gear construction



Feb. 25, 1930.

E. A. NELSON STEERING GEAR CONSTRUCTION Filed May 21, 192s I. 2 Smeets-Sheetl 1 lil/l,

INVENTOR.

EMIL f. NELSON A TTORNE Y.

Feb. 25, 1930. E. A. NEL-SON 1,748,615

STEERING GEARl CONSTRUCTION Filed May 21. 1928' 2 sheets-sheet 2 lmp y Z5 d r/ 30 l 40 {ll/1111111] INVENTOR.

By EM/L NELso/v i ATTORNEY.

"2 5: gear fofthe'fworm typejin which the worm heel portion thereof is provided with a single iiiviiit unison,r ork Patented FebaZS, 1930V Dn'rnoi'r, 'MICHIGAN- sTEEniNG-GEAR ooivsrnuo'rioiv Application fue@ nay 21,

This invention relates to steering gears for motor vehicles and thelike, the Vprincipal ob#l VYjectbeing the provision ofy an improvedvoonstruction, simple' in design, economical to -15 manufacture, and eificient in operation.

10 'the device-is increased Y tional: constructions. ,f

" forms a part;

Another object is to' provide a steering gear having 'a minimum. number of parts and a Vmaximum amount of bearing surfaces wherebythe reliability and lthe'length of lifey of overthat of conven- Another object is to provide avst'eering gear with novel meansL for reducing i kick .back

through the same without sacrificing the-free operation of the gear.` Y

'Another object is tovprovide a novel means yforcompensating forfwear. in a steering lgear of the type described.; i

'Anotherobj ect is to provide a steeringgear of the worm'type in which the maximum di# ameter of the worm is utiflizedduring normal straight dr-iving of the vehicle of which itr A further .object is to provide a steering tooth formed separately, form its support whereby it may be ymade of a material highly 'i resistant to wear.

The above being among thev objects of the present invention` the same consists in certain features-of construction and combinations of parts to be hereinafter describediwith lreference tothe accompanying drawings, and then olaimed,lhaving the abovei-and otherobjects rin view. Y, .Y i f In the accompanying'drawingswhich illustrate suitable embodimentsof the present in 40;', ventionv andin which like numerals refer to like parts throughout the several different Fig. 1 is a side elevation of a steering-gear constructed in accordancewith the present-in-Y ventionlfv ..4-

` Fig, ,2 isan enlarged vertical sectional view of ,thelower 'end of'the steering gear taken v throughV they axis of the post. i

' Fig; la" vertical sectional viewmtaken on the line 3;?1' of Fig. 2.

Fig-'14 a fragmentary vsectional viewH of 192s. kserial No. 279,269.

'the' steering shaft'takenas von the line Orrige.

Fig. 5 isa side elevation of theworm mem- Y.

ber employed in the presentinvention.

' I show in the accompanying drawings a steering gearof .the typev designed'tobe einL ployed on motor vehicles comprising a 'housing 10 which carries the usual jacket 11' at lthe upper end of whichisvpositioned the usual steering wheel 12. 'The housingflO may be provided .with an integral end wall 13 at its lower end and withv a member"14 threaded `into the opposite end thereof, the jacket 1-1v .directly engaging the member 14 as shown.

TNithin the housing 10 is azwormm'ember'l forniedv to provide bearingcones 16 at its opposite ends which are adapted to cooperate with the rollersl? bearing against the races 18 which, in turn, are carriedby the inner walls ofthe housing 10." The worinmember 151s secured by suitable means such as the key 19 against rotation tothe steering tube '20',

which extends therethrough and up through the jacket 11to the steering wheel 12 to whichv i-t is suitably secured. yAs shown best in Fig. 5, thecentral portion of the worm member'15 is formed lto a spherical Vshape in which relatively largeV worm grooves 21 arev formed'.

The lead of thegrooves 21 on the portion V15 may be constant,"or. may increase or decrease in degree away from fthe maximumdiameter of theportion 15, as desired. rl`he axial position of the wormy membery 15 is Agoverned by the position of the races 18, the distance 'between which ismadjusta'bly controlled `by the member 14 which may be locked in vadj usted positionin a conventional manner by the bolt respectively- A threadedcollar 29 is received Within the housing 10 in engagement with the 22 extending through the'slotted end portion Y ried by the cap 34 extends through the slot in the housing 10 and is adapted to engage one of the notches 32 so as to lock it in axially adjusted position. Upon removal of the cap 34 and member 33, a screw driver or other instrument may be Vinserted through the slot 35 to rotate the collar 29 so as to vary the axial position thereof. The cap` or cover member 30 is provided with a plurality of axially parallel fingers 36 adjacent its periphery and the adjacent wall' of the housing 10 is provided with a removabley locking finger 3 7 secured thereto by a bolt 38, the finger 37 being adapted to engage the fingers 36 to lock the cap or cover member 30 in its rotated and therefore axially adjusted position with relation to the housing 10. The shaft 25 has formed thereon within the housingl() a cylindrical portion 39 which extends into almost contacting relationship with the wall 26 and is of a length commensurate with the distance between the collar 29 and cap or cover member 30. The portion 39 is provided with a pilot or extension 40 at the end thereof opposite the shaft 25 which is received Within the bushing 31 and therefore acts as an outboard bearing for the portion 39.

The cylindrical portion 39 is provided Awith an enlarged central opening 41, the axis vof whichv intersects and is perpendicular to the axis of the portion 39 and within which the worm member 15 is freely received. The cylindrical portion 39 is provided with an opening 42 which extends from one end face to the other end faceV thereof and intersects the opening 41, the opening 42 being slightly iiiclined to the axis of the portion 35 in two directions7 one direction being in' accordance with the lead of the grooves 21 in the worm member 15 and the other with respect to the outer surface of the portion 39. Secured within the opening 42 is a tooth member 43 `which is adapted to engage the groove 21 in the worm 15 and therefore servesv as a portion of the worm wheel cooperating with the worm l5.` Thus, when the worm 15 is rotated, the tooth 43 is caused-to follow the lead of the groove 21 which it engages and thus causes the cylindrical portion 39 to rotate about its axis in accordance with the direction of rotation of the worm 15. The diameter of the opening 41 is such as to permit sufficient rotation of the portion 39 and shaft 25 about the worm 15 that the conventional amount of movement of the steering arm-,44 secured to the end of the 'shaft 25 is obtainable. The tooth 43 being formed separately fromV the member 39, and bein-g of a relatively simple form,.permits it to be made of a material extremely resistant to wear, such as of that class of tool steel mavto the left and following up'such movement of the collar 29l by like movement of the cap or cover 30, thus moving the portion 39 and shaft 25 to the right` so as to bring the tooth 43 into closer relationship with the worm, and the cap `and cover 30 and collar 29 also cooperates with the portion 39 to control the permissible .amount of axial movement of the portion 39. It will also be apparent that the member v14 controls the permissible amount of axial movement of the worm 15 with respect to the housing 10. The resulting simplicity of adjustment over conventional construction is readily apparent.V

In practice I prefer to till the interiorof the housing 1() with the usual heavy lubricant. This lubricant not only lubricates the wearing surfaces of the device but covers the interior wall 26 and is carried between such wall and the portion 39. As before described, the external diameter of the portion 39 is but slightlysmaller than the diameter of the wall 26 with the result that when the portion 39 is turned relative to the housing, a relative large area of lubricant on the. wall 26 must be `sheared during the turning` movement. I provide this construction so that any shocks to which the wheels of vthe vehicle are subjected to and which are normally transmitted through the steering arm 44, shaft 25 and tooth 43 tothe worm 15 and thence to the steering wheel 12, will be dampened due to the fact that in being so transmitted to the steering wheel 12, they must shear the large film of oil on the surface 26. llind that this feature materially dampens such shocks without materially interfering with the free operation of the steering gear itself.V

It may also be noted that by this consti'uction' in which the worin engages an internal worm wheel, during normal straight driving, which constitutes by far the greatest percentage of driving of a vehicle, the maximum diameter of the worm is in engagement with the tooth member 43, so that any wear between the tooth member 43 and'its :cooperating groove 21 in the worin will allow a minimum of backlash to be apparent at the steering wheel 12.l

Although I have shown in the accompanying drawings the axial line of the steering shaft 25 as perpendicular to and intersecting the axis of the worm 15, it will be readily apparent that wherey desirable the axis* of the shaft 25 may be inclined to the axis of the worm, or the axialline of the shaft 'may be positioned outV of intersecting Yrelationship With respect tothe axis-` of tlie'Worm any kamount found desirable, lthe contour of the;` k,Worm kbeing Vvaried in such `cases to meet the particular requirements arising bysuch'.

fchangesf" i Formalrchanges may be made in the spe-j cific embodiment of the inventionfdescribed Without departing fromthe spiritl or sub-k Lsta-nce of the broad invention, the scope of which is-commensurate with the appended claims. i

Whaticiimis: y 1..In combination,` a rotatable shaft, a

wvorm'positioned perpendicularly to the axis Y of said shaft, and an extension'carried by said shaft extending over saidvvvorni and provided With aninternal type of` tooth extending tangentially With respect to saidlvvorm andin engagenienttherevvith. a y2. Iiicombination, a rotatable Worm, a rotatable shaft positioned with its Vaxial line perpendicular to and intersecting the axis of said Worm, a part carried by said shaft extending over said Worin, and a tooth extending tangentially with respect to said Worm carried by said part in engagement With said 3. In combination, a rotatable Worm, a roi tatable shaft'positioned With its axial line at an angle to the axis of said Worm, a part carried by said shaft bridging said Worm, a pilot for said part on the side of said Worm opposite said shaft, and a tooth extending tangentially with respect to said Worin Carried by said'part in engagement with saidvvorm whereby rotation of said Worm causes rotation of said shaft. f

ably mounted in said housing With its axial line at an angle to the axisof and intersectving the surfaceofsaid Worm, said' shaftbeing provided witha part extending over said'v Worin in freely spaced relation in respect l' thereto, and a tooth extending tangentially with respect to said Worin carried by said part in engagement With said Worm,

,6. lIn combination, a housing, pairv of shafts rotatably Y mounted in said housing With their axial lines at an angle to each other, a Worm secured to one of said shafts for equal rotation therewith, a part, carriedv by the otherlof said shafts provided With a central opening in Which'said Worm is freely received, and Va tooth member carriedby said member in a tangential 'direction Withy re-V spectto said- Worm Vand'ex'posed in fsaidopening for engagement with saidy Worm.'y

Y7.: In-fcombinatiomi arhousing, a vpair of shafts ,rotatably4 mounted in said housing With their axiallines at an angle to eachoth-y er,r`a' Worm secured to one of saidl shafts 'for equal rotation therewith, a part carried.v by the other ofsaid shafts extendingA over said Worin, anda tooth on said part engagingv said Worm', said'p'art and saidl housing having'cooperating surfaces adapted to be covered by a lubricant and providing damping means for shocks transmitted5between'said shafts;` 8. In, combination, la housing, a Worm 1rotatably mountedithereim a shaft rotatably mountedjin said. housing lWithr its axis at4 an soY angleto the axialline of said Worm, said Y Y shaft being provided yWith an enlarged part provided With a cylindrically'shaped outer surface, the adjacent inner surfacev of said housing extending into substantially contacting relationship withv respect to said outer surface, said enlarged part extending over said Worm, and a tooth onv said part engagin said Worm.

9. In combination, a housing, a Worm rotatably mounted therein, a shaft rotatably l mounted in said housing With its axial line `at an angle to the axis of said Worm, a part carried by said shaft extending over said Worin, a tooth carried by said part in engagement with said Worm, said .tooth being inclined to the axis of said shaft, and means for v adjusting the axial position of said part whereby to'control the clearance between said tooth and said Worm. i

l0. In combination, a housing, a Worm rotatably mounted therein, va shaft rotatably mounted in said housing With its axial line ternal Worm Wheel part' carried by said shaft bridging said WormA and provided with a,

tooth engaging said Worm, and means carried by said housingl adJustable` axially of said shaft for controlling` the position of said tooth transversely to said Worm.

' ll. In combination, a housing, a Worm mounted in said housing with its axial rline fico 1105 at an angle to the axis of said Worm, anfinrotatably mounted therein, a shaft rotatably,

at an angle to the axis of said Worin, a part onkv said shaft bridging said Worm, an opening insai'd part tangentially disposed relative' to said Worm intersecting the inner surface l thereof, and a tooth member insaid opening engaging said Worin. l l2. In combination, a housing, a worm rotatably mounted therein', a shaft rotatably mounted in said housing with itsv axial line l. at an angle to the axis of said Worm, an eni largedvpart on said shaft provided with an opening in which said Worm is received, a second opening in said part tangentially disposed relative to said Worm intersecting the first mentioned opening,and a tooth member received Within said second member engagmg said Worm Within said first mentioned openmfr.

13. In combination, a housmgworm rotatably mounted therein, a shaft rotatablyVv mounted in said housing with its axial line at an angle to the axis of Said Worm, an en- 12u-ged part on said 4shaft provided With an opening in which said Worm is received, `:1- second opening in Said part intersecting the first mentioned opening, and 'a tooth member received .Within said second member engagopening, said tooth member extending at an angle to the axis ofsaid shaft wherebyv axial movement Vof said shaft will vary the dearance between said tooth and said Worm.

EMIL A.Y NELSON.

mg'sad Worm Within said first mentioned Y 

